The custom expansion of select operations in the RISC-V backend
interferes with the matching of cmov instructions. Legalizing
select when the Zbt extension is available solves that problem.
Reviewed By: lenary, craig.topper
Differential Revision: https://reviews.llvm.org/D93767
We can use these instructions for single bit immediates that are too large for ANDI/ORI/CLRI.
The _10 test cases are to make sure that we still use ANDI/ORI/CLRI for small immediates.
Differential Revision: https://reviews.llvm.org/D92262
This uses the shiftop PatFrags to handle the masked shift amount
and unmasked shift amount cases. That also checks XLen as part
of the masked amount check so we don't need separate RV32 and RV64
patterns.
Differential Revision: https://reviews.llvm.org/D91016
Out of bounds shifts are undefined and these instructions mask
their shift amount before use. So we don't need to see a mask
in order to select the instructions.
This patch provides optimization of bit manipulation operations by
enabling the +experimental-b target feature.
It adds matching of single block patterns of instructions to specific
bit-manip instructions from the single-bit subset (zbs subextension) of
the experimental B extension of RISC-V.
It adds also the correspondent codegen tests.
This patch is based on Claire Wolf's proposal for the bit manipulation
extension of RISCV:
https://github.com/riscv/riscv-bitmanip/blob/master/bitmanip-0.92.pdf
Differential Revision: https://reviews.llvm.org/D79874
Sam Elliott